Biased attention towards negative schematic expression in abstinent heroin abusers

Drug dependents exhibit biases when evaluating emotional facial expressions; however little is known about their emotional biases appearing at the pre-awareness stage. The present study examined whether abstinent heroin abusers preferentially attended to facial expressions with particular emotion type.

Thirty-seven abstinent heroin abusers (AH participants), twenty normal healthy controls (NC participants), and nineteen individuals with moderate anxiety/depression disorders (PC participants) were included in the study. Participants searched displays containing a varying number of schematic neutral faces for a unique schematic face expressing either a positive or a negative emotion.

Results revealed that AH participants had generally shallower search slopes for locating the negative target face than those for locating the positive one, whereas no such difference was found on NC participants or PC participants.

It suggested that abstinent heroin abusers are biased to attend to negative expression more effectively than attend to positive expression. We proposed that this may result from abstinent heroin abusers' repeated exposure to people's negative expressions in their living environment or a pre-existing emotional processing deficit which could initiate the development of drug abuse behaviour.